package gemtext

import (
	"bufio"
	"io"
)

// Parse parses the full contents of an io.Reader into a gemtext.Document.
func Parse(input io.Reader) (Document, error) {
	rdr := bufio.NewReader(input)

	var lines []Line
	inPFT := false

	for {
		raw, err := rdr.ReadBytes('\n')
		if err != io.EOF && err != nil {
			return nil, err
		}

		var line Line

		if inPFT && (len(raw) < 3 || raw[0] != '`' || raw[1] != '`' || raw[2] != '`') {
			line = PreformattedTextLine{raw: raw}
		} else {
			line = ParseLine(raw)
		}

		if line != nil && line.Type() == LineTypePreformatToggle {
			if inPFT {
				toggle := line.(PreformatToggleLine)
				(&toggle).clearAlt()
				line = toggle
			}

			inPFT = !inPFT
		}

		if line != nil {
			lines = append(lines, line)
		}

		if err == io.EOF {
			break
		}
	}

	return Document(lines), nil
}